In one of yesterday’s discussions this criticism of Ayn Rand’s theory of concepts and propositions from the position of modern dualist (in the sense of dualism between the world and concepts) philosophy by Michael Huemer went up. However, what I want to do here is not to defend Rand’s theory but to show that Huemer fails to prove two very important points.
He starts with defening the necessity of distinction between sense and reference:
The need for distinguishing the ‘sense’ of a word from its ‘reference’ is shown by examples like this:
Oedipus, famously, wanted to marry Jocaste, and as he did so, he both believed and knew that he was marrying Jocaste. The following sentence, in other words, describes what Oedipus both wanted and believed to be the case:
(J) Oedipus marries Jocaste.
However, Oedipus certainly did not want to marry his mother, and as he did so, he neither knew nor believed that he was marrying his mother. The following sentence, then, describes what Oedipus did not want or believe to be the case:
(M) Oedipus marries Oedipus’ mother.
But yet Jocaste just was Oedipus’ mother. That is, the word “Jocaste” and the phrase “Oedipus’ mother” both refer to the same person. Therefore, if the meaning of a word is simply what it refers to, then “Jocaste” and “Oedipus’ mother” mean the same thing.
It does follow from this example that the Randian theory of meaning is mistaken but it does not follow that distinguishing sense from reference is the only alternative. The alternative that I have in mind is the idea that it is possible for someone to have only a limited grasp of a certain concept and thus to refer to the referent of such a concept only in a limited sense. After seeing a tiger, a child may, while still not knowing that a tiger is a carnivorous mammal with a certain areal of existence, etc., realize that tiger has big teeth and a lot of strength. The same is true of Oedipus and Jocaste.
Another important point by Huemer concerns the existence of Kantian a priori.
By an item of “empirical knowledge” I mean something that is known that either is an observation or else is justified by observations. A priori knowledge is that which is not empirical – i.e., an item of knowledge which is not an observation and which is not justified by observations.
Note the word “justified”. I do not say that a priori knowledge does not depend causally on observations. I do not say that the concepts required to understand it are innate or formed without the aid of experience. I only maintain that a priori knowledge is not logically based on observations. In other words, if x is an item of a priori knowledge, then there is no observation that is evidence for the truth of x – but we still know x to be true.
He provides an example with addition:
How about this, then: I see one orange, over here. Then I see another orange, over there. I put the two oranges together. I count them, and get the result “2”. I therefore conclude that 1 orange plus 1 orange = 2 oranges. Perhaps by doing this experiment with a lot of different kinds of objects, I eventually conclude (inductively) that 1 + 1 = 2, regardless of what type of objects are being counted. Thus, observation has confirmed (B). Perhaps by also confirming a lot of other equations, I might also be able to inductively support the axioms of arithmetic.
This idea, of course, involves a confusion about the nature of addition. Addition is not a physical operation. It is not the operation of physically or spatially bringing groups together, and the equation (B) does not assert that when you physically unite two distinct objects, you will wind up with two distinct objects at the end.
Addition is not any and not only physical grouping of distinct objects. But it does not mean that it is not instantiated in some such groupings (from observing which everyone of us has learned the meaning of addition). Thus, there is no problem in saying that 1+1=2 is evidenced by putting two oranges together. And thus the knowledge that 1+1=2 is not a priori. In fact, there is probably no such thing as Kantian a priori knowledge.